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1.
Surg Clin North Am ; 102(2S): e1-e6, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35397871

RESUMO

Neck mass is a common first sign of malignancy in adult patients. Timely diagnosis can prevent disease progression. Initial evaluation of a neck mass includes creating a plan for obtaining further diagnostic information such as through imaging and tissue diagnosis. Fine-needle aspiration (FNA) can be done with or without ultrasound (US) guidance and is commonly done as an alternative to core biopsy and open biopsy. The accuracy of US-guided FNA has been shown to supersede that of palpation-guided FNA. Moreover, in-office US-guided FNA has become more accessible over time and can improve time to diagnosis.


Assuntos
Biópsia Guiada por Imagem , Adulto , Biópsia por Agulha Fina/métodos , Humanos , Ultrassonografia
2.
Laryngoscope ; 120(10): 1922-30, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20824643

RESUMO

BACKGROUND: The expansion of endoscopic endonasal skull base surgery has resulted in an increased demand for reconstructive options. Reconstruction with vascularized tissue has proven indispensable for reliably separating the cranial contents from the paranasal sinuses following extended endoscopic endonasal approaches (EEA). The introduction of the Hadad-Bassagasteguy flap (vascular pedicle nasoseptal flap, HBF) at our institution decreased our postoperative cerebral spinal fluid (CSF) leak rates from more than 20% to less than 5%. The HBF is not always available, as the nasoseptal area or its vascular supply can be compromised by tumor or prior surgery. In an attempt to keep pace with rapidly expanding reconstructive requirements, we present the anatomic and cadaveric foundations for novel modifications of the facial artery musculo (-mucosal) (FAM[M]) and buccinator flaps to allow vascularized reconstruction of the skull base. STUDY DESIGN: Feasibility. Cadaveric study. METHODS: Using cadaver dissections and measurements, we investigated the feasibility of transposing pedicled buccinator myo/myomucosal flaps into the nasal cavity and skull base. Both muscular and myomuscular flaps were raised, and techniques for transposition into the nasal cavity were investigated. Three fresh and six preserved human specimens were dissected. RESULTS: Pedicled facial buccinator flaps with and without mucosa were transposed into the nasal cavity using a variety of maxillary osteotomies. No facial incisions were required. It was demonstrated that the flaps reach the anterior skull base and planum sphenoidale. CONCLUSIONS: The transposition of pedicled buccinator muscle flaps with and without mucosa into the nasal cavity could reach the anterior skull base and planum sphenoidale, if the appropriate surgical technique is used. The pedicled Facial Buccinator Flap holds significant potential as a reconstructive alternative for a variety of skull base defects, alone or in combination with existing reconstructive options. 2010.


Assuntos
Cavidade Nasal/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Base do Crânio/cirurgia , Retalhos Cirúrgicos , Cadáver , Endoscopia , Estudos de Viabilidade , Humanos , Osteotomia
3.
Laryngoscope ; 118(12): 2102-6, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19029856

RESUMO

OBJECTIVES: Defects after endoscopic expanded endonasal approaches (EEA) to the skull base, have exposed limitations of traditional reconstructive techniques. The ability to adequately reconstruct these defects has lagged behind the ability to approach/resect lesions at the skull base. The posteriorly pedicled nasoseptal flap is our primary reconstructive option; however, prior surgery or tumors can preclude its use. We focused on the branches of the internal maxillary artery, to develop novel pedicled flaps, to facilitate the reconstruction of defects encountered after skull base expanded endonasal approaches. STUDY DESIGN: Feasibility. METHODS: We reviewed radiology images with attention to the pterygopalatine fossa and the descending palatine vessels (DPV), which supply the palate. Using cadaver dissections, we investigated the feasibility of transposing the standard mucoperiosteal palatal flap into the nasal cavity and mobilizing the DPV for pedicled skull base reconstruction. RESULTS: We transposed the palate mucoperiosteum into the nasal cavity through limited enlargement of a single greater palatine foramen. Our method preserves the integrity of the nasal floor mucosa, and mobilizes the DPV from the greater palatine foramen to their origin in the pterygopalatine fossa. Radiological measurements and cadevaric dissections suggest that the transposed, pedicled palatal flap (the Oliver pedicled palatal flap) could be used to reconstruct defects of the planum, sella, and clivus. CONCLUSIONS: Our novel modifications to the island palatal flap yield a large (12-18 cm(2)) mucoperiosteal flap based on a approximately 3 cm pedicle. The Oliver pedicled palatal flap shows potential for nasal cavity and skull base reconstruction (see video, available online only).


Assuntos
Endoscopia , Neoplasias da Base do Crânio/cirurgia , Base do Crânio/cirurgia , Retalhos Cirúrgicos/irrigação sanguínea , Fossa Craniana Posterior/cirurgia , Estudos de Viabilidade , Humanos , Artéria Maxilar/cirurgia , Cavidade Nasal/cirurgia , Sela Túrcica/cirurgia , Base do Crânio/irrigação sanguínea , Coleta de Tecidos e Órgãos/métodos , Tomografia Computadorizada por Raios X
4.
Mol Cancer Ther ; 4(1): 23-31, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15657350

RESUMO

Aberrant overexpression of antiapoptotic members of the Bcl-2 protein family, including Bcl-2 and Bcl-X(L), contributes to malignant transformation and subsequent resistance to traditional chemotherapeutics. Thus, these proteins represent attractive targets for novel anticancer agents. The small molecule, gossypol, was initially investigated as a contraceptive agent, but subsequently has been shown to possess anticancer properties in vitro and in vivo. Recently gossypol has been found to bind to Bcl-X(L) and, with less affinity, to Bcl-2. Here we investigate the ability of the (-) enantiomer of gossypol, (-)-gossypol, to overcome the apoptosis resistance conferred by Bcl-2 or Bcl-X(L) overexpression in Jurkat T leukemia cells. (-)-Gossypol potently induced cell death in Jurkat cells overexpressing Bcl-2 (IC50, 18.1+/-2.6 micromol/L) or Bcl-X(L) (IC50, 22.9+/-3.7 micromol/L). Vector-transfected control cells were also potently killed by (-)-gossypol (IC50, 7.0+/-2.7 micromol/L). By contrast, the chemotherapy drug etoposide only induced efficient killing of vector-transfected cells (IC50, 9.6+/-2.3 micromol/L). Additionally, (-)-gossypol was more efficient than etoposide at inducing caspase-3 activation and phosphatidylserine externalization in the setting of Bcl-2 or Bcl-X(L) overexpression. (-)-Gossypol-induced apoptosis was associated with Bak activation and release of cytochrome c from mitochondria, suggesting a mitochondrial-mediated apoptotic mechanism. Moreover, (-)-gossypol treatment of isolated mitochondria purified from Bcl-2-overexpressing cells also resulted in cytochrome c release, indicating a possible direct action on Bcl-2 present in the mitochondrial outer membrane. Taken together, these results suggest that (-)-gossypol is a potent and novel therapeutic able to overcome apoptosis resistance by specifically targeting the activity of antiapoptotic Bcl-2 family members. (-)-Gossypol may be a promising new agent to treat malignancies that are resistant to conventional therapies.


Assuntos
Apoptose/efeitos dos fármacos , Gossipol/farmacologia , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Etoposídeo/toxicidade , Humanos , Células Jurkat , Mitocôndrias/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/efeitos dos fármacos , Transfecção , Proteína bcl-X
5.
Clin Cancer Res ; 10(22): 7757-63, 2004 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-15570010

RESUMO

PURPOSE: Bcl-xL overexpression is common in head and neck squamous cell carcinomas (HNSCC) and correlates with resistance to chemotherapy. Thus, a nonpeptidic, cell-permeable small molecule that mimics the BH3 domain of proapoptotic proteins may inhibit Bcl-xL function and have therapeutic potential for HNSCC by overcoming drug-resistance. (-)-Gossypol, the levorotatory isomer of a natural product isolated from cottonseeds and roots, was recently discovered to bind to the BH3 binding groove of Bcl-xL and Bcl-2. EXPERIMENTAL DESIGN: We investigated the in vitro effects of (-)-gossypol on HNSCC cell lines as well as on fibroblast and keratinocyte cultures by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell survival assays and assessed the results with respect to Bcl-2 family protein expression. RESULTS: We observed dose-dependent growth inhibition of 10 HNSCC cell lines at biologically achievable doses (2.5-10 micromol/L). (-)-Gossypol doses required to inhibit the growth of human fibroblast cell lines by 50% were 2- to 10-fold higher than for HNSCC cell lines. To inhibit human oral keratinocyte growth by 50%, (-)-gossypol concentrations were 2-to 3-fold higher than for HNSCC cell lines. CONCLUSIONS: There is a direct correlation between Bcl-xL-to-Bcl-xS ratios and sensitivity to (-)-gossypol. This agent induced apoptosis in a much higher proportion of cells with wild-type p53. Importantly, cell lines resistant to cisplatin were very sensitive to (-)-gossypol. These results demonstrate that (-)-gossypol has potent antitumor activity in HNSCC in vitro. This agent may be developed as a novel therapeutic agent for HNSCC, either alone or in combination with existing chemotherapeutic agents.


Assuntos
Carcinoma de Células Escamosas/tratamento farmacológico , Gossipol/química , Gossipol/farmacologia , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Fragmentos de Peptídeos/química , Proteínas Proto-Oncogênicas/química , Apoptose , Western Blotting , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Dimerização , Relação Dose-Resposta a Droga , Resistência a Medicamentos , Fibroblastos/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Marcação In Situ das Extremidades Cortadas , Concentração Inibidora 50 , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-bcl-2/química , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/farmacologia , Sais de Tetrazólio/farmacologia , Tiazóis/farmacologia , Fatores de Tempo , Proteína Supressora de Tumor p53/metabolismo , Proteína bcl-X
6.
Mol Cancer Ther ; 3(11): 1343-54, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15542773

RESUMO

Overexpression of the antiapoptotic proteins Bcl-2 and Bcl-XL is commonly observed in human malignancies and contributes to chemotherapy and radiation resistance. Bcl-2 and Bcl-XL inhibit apoptosis by binding to proapoptotic proteins such as Bax, thereby preventing chemotherapy-induced or radiation-induced release of cytochrome c from mitochondria and subsequent activation of the caspase protease cascade. Efforts to inhibit Bcl-2 or Bcl-XL function in tumor cells have focused on developing agents to inhibit the interactions of these proteins with proapoptotic proteins. Peptides derived from the BH3 domains of proapoptotic proteins have been shown to disrupt the interactions of Bcl-2 and Bcl-XL with key binding partners in cell-free reactions and to promote cellular apoptosis. However, less is known about the targets of BH3 peptides in intact cells as well as the sequence, length, and conformational requirements for peptide biological activity. In this report, we show that cell-permeable Bax BH3 peptides physically disrupt Bax/Bcl-2 heterodimerization in intact cells and that this disruption correlates with peptide-induced cell death. A point-mutant, control peptide that failed to disrupt intracellular Bax/Bcl-2 interactions also failed to promote apoptosis. To determine important sequence, length, and structural requirements for peptide activity, we generated and systematically analyzed the biological activities of 17 Bax BH3 peptide variants. Peptides were quantitatively examined for their ability to inhibit Bax/Bcl-2 and Bax/Bcl-XL heterodimerization in vitro and to promote cytochrome c release from mitochondria isolated from Jurkat, HL-60, U937, and PC-3 cells. Our results define 15 amino acids as the minimal length required for Bax BH3 peptide biological activity and show that amino acids COOH terminal to the BH3 core sequence are less critical than those located NH2 terminal to the core. In addition, circular dichroism spectroscopy revealed that high alpha-helical content generally correlated with, but was not sufficient for, peptide activity. Taken together, these studies provide a basis for future optimization of Bax BH3 peptide as a therapeutic anticancer agent.


Assuntos
Apoptose/efeitos dos fármacos , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/química , Proteínas Proto-Oncogênicas c-bcl-2/farmacologia , Sequência de Aminoácidos , Linhagem Celular Tumoral , Dicroísmo Circular , Citocromos c/metabolismo , Dimerização , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Dados de Sequência Molecular , Mutação/genética , Fragmentos de Peptídeos/genética , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Alinhamento de Sequência , Transdução de Sinais/efeitos dos fármacos , Proteína X Associada a bcl-2
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